A Case Report of Rare Syndrome-One and a Half Syndrome

This case report describes a 52 year old male who presented with acute headache, giddiness, vomiting, and diplopia, later identified as one and a half syndrome linked to a pontine hemorrhage in the setting of poorly controlled hypertension. Ocular findings showed horizontal gaze palsy with preserved vertical movements and convergence, supported by neuroimaging that revealed chronic infarcts with superimposed brainstem hemorrhage and vascular variation on angiography. The clinical course highlights how a unilateral pontine lesion affecting the paramedian pontine reticular formation, abducens nucleus, and medial longitudinal fasciculus produces the classic eye movement pattern seen in this syndrome. Early blood pressure control led to gradual improvement in symptoms, underscoring the role of timely recognition and focused management in cerebrovascular causes of complex gaze disorders.